Modern Australian


Giant sea scorpions were the underwater titans of prehistoric Australia

  • Written by Russell Dean Christopher Bicknell, Post-doctoral researcher in Palaeobiology , University of New England

Let’s turn back the hands of time. Before extinction knocked dinosaurs off their pillar, before the “Great Dying” extinction wiped out 95% of all organisms – we had the Paleozoic Era.

During this age in Earth’s history, between 541 million and 252 million years ago, arthropods (animals with exoskeletons such as insects, crustaceans, scorpions, and horseshoe crabs) were exploring the extremes of size, from tiny to huge.

In fact, some Paleozoic arthropods represent the largest animals on Earth at the time. If you were to take a swim in the Paleozoic oceans, you may have been fortunate (or unfortunate) enough to find one of the most fearsome of these extinct arthropods: the sea scorpions, Eurypterida.

Our new research, published in Gondwana Research, is the most comprehensive collection of information on these fascinating creatures that once roamed Australian waters.

Giant sea scorpions were the underwater titans of prehistoric Australia A Eurypterus remipes fossil. This sea scorpion existed more than 400 million years ago and was usually less than one foot in length, but relatives are believed to have reached up to eight feet. H. Zell/Wiki commons, CC BY-SA

A sight to behold

Although Eurypterida looked broadly like scorpions (with a similar body shape, albeit built for swimming), they were not. They were more like the cousins of modern scorpions.

An exceptional part of the sea scorpion evolutionary story is how they fit into the narrative of Paleozoic gigantism.

Read more: Fossils of huge plankton-eating sea creature shine light on early arthropod evolution

Sea scorpions include the largest marine predators to have ever arisen in the fossil record, including one species thought to have been more than 2.5 metres long, Jaekelopterus rhenaniae. Back then, some of these giants were effectively in the same place in their food web as the modern great white shark.

These likely agile swimmers would have used their large front limbs, armed with claws, to grab their prey, which they would then crush between the teeth-like structures on their legs (called gnathobasic spines).

While we’re not sure exactly what these large animals ate, it’s likely fish and smaller arthropods would have been on the menu. And if humans had been around swimming in the sea, maybe us too!

Giant sea scorpions were the underwater titans of prehistoric Australia The size of the largest extinct sea scorpions, relative to a human. Slate Weasel/Wiki commons. Modified.

A fascinating (but murky) history

Australia is famous for its array of curious animals, including unique modern species such as the platypus. And this uniqueness extends far into the fossil record, with sea scorpions being a case in point.

But the scientific record and study of Australian sea scorpions has been patchy. The first documented specimen, published in 1899, consisted of a fragmented exoskeleton section found in Melbourne.

Prior to our new research examining the completeness of the group in Australia, there were about ten records – and only one other attempt to pool everything together. As such, the diversity and spread of these fossils was fairly uncertain.

For us, revisiting these amazing fossils resulted in a few trips to different Australian museums. We also had specimens sent to us at the University of New England to examine in person.

Read more: The mighty dinosaurs were bugged by other critters

This journey of palaeontological discovery uncovered many sea scorpion fossils than hadn’t previously been noted. As a result, we now have evidence of a possible six different groups that existed in Australia.

Collating these specimens together in our most recent publication, we illustrate the Pterygotidae (the family of sea scorpions that reached 2.5 metres long) dominated the group’s Australian fossil record. Although this had been noted before, the abundance of material from different locations and time periods, especially from Victoria, was unexpected.

Giant sea scorpions were the underwater titans of prehistoric Australia Examples of Australian sea scorpion fossils, their two groups and the time range. Blue represents the family Pterygotidae and orange represents the family Adelophthalmidae.

Back to the source

Besides showcasing the largest number of Australian sea scorpions, our paper also outlines the overall lack of information on these animals.

Despite there being much fragmented material, there is only one (mostly) complete specimen, Adelophthalmus waterstoni, measuring just 5.7cm long.

Future research will involve revisiting the sites where these specimens were originally collected, in the hope of finding more complete specimens. Not only will this help document Australian sea scorpion species better, it will also allow for a more complete understanding of the environments in which they lived.

Ultimately, one thing is clear – there is much left to uncover about these titans that swam through Australia’s prehistoric oceans.

The authors thank Natalie Schroeder of the Commonwealth Palaeontology Collection for her help with this project.

Authors: Russell Dean Christopher Bicknell, Post-doctoral researcher in Palaeobiology , University of New England

Read more https://theconversation.com/giant-sea-scorpions-were-the-underwater-titans-of-prehistoric-australia-141290

NEWS

Indonesia's coronavirus fatalities are the highest in Southeast Asia. So, why is Jokowi rushing to get back to business?

MAST IRHAM/EPAIndonesia is still struggling to manage the COVID-19 pandemic. Its fatalities are the worst in Southeast Asia, but so far the most dire predictions have not come true. And...

Yes, it looks like Victoria has passed the peak of its second wave. It probably did earlier than we think

It’s hard to recall a time when we didn’t nervously await the announcement of Victoria’s daily COVID-19 case numbers each morning.It was certainly disconcerting when the state recorded more than...

Voting is an essential service too. New Zealand can't be afraid to go to the polls, even in lockdown

GettyImagesIf we can do our grocery shopping under lockdown, we can vote under lockdown too.As much as supermarkets and pharmacies, the general election is an essential service and it must...

how a new carbon dating timeline is changing our view of history

ShutterstockGeological and archaeological records offer important insights into what seems to be an increasingly uncertain future. The better we understand what conditions Earth has already experienced, the better we can...

Should you hold your child back from starting school? Research shows it has little effect on their maths and reading skills

ShutterstockWhether to hold a child back from starting school when they are first eligible is a question faced by many parents in Australia each year.If you start a child at...

These historic grasslands are becoming a weed-choked waste. It could be one of the world's great parks

Adrian Marshall, Author providedVolcanic plains stretching from Melbourne’s west to the South Australian border were once home to native grasslands strewn with wildflowers and a vast diversity of animals. Today...

coronavirus leaves international students in dire straits

ShutterstockMany international students in private rental housing in Sydney and Melbourne were struggling before COVID-19 hit. Our surveys of these students before and during the pandemic show it has made...

Public housing renewal can make tenants feel displaced in their home, even before any work begins

Public housing estate redevelopments that displace residents to other suburbs are highly disruptive whereas projects that allow them to remain are suggested to be better. We tested this assumption through...

Timing the share market is hard – just ask your super fund

ymgerman/ShutterstockThe past financial year has been one of the most volatile on record for stock markets, yet almost every Australian super fund has delivered similar returns. This not only demonstrates...

Got your bag? The critical place of mobile containers in human evolution

ShutterstockToday, bags are everywhere — from cheap canvas ones at the supermarket to designer handbags costing up to US$2,000,000. But archaeological evidence shows we have been using mobile containers —...

Royal Commission into Aged Care reminds Health Department Secretary Brendan Murphy it sets the rules

The Royal Commission into Aged Care put the Secretary of the Federal Health Department, Brendan Murphy, firmly in his place when he tried to make an opening statement to attack...

Russia's coronavirus vaccine hasn't been fully tested. Doling it out risks side effects and false protection

A scientist holding a coronavirus vaccine at the Nikolai Gamaleya National Center of Epidemiology and Microbiology in Moscow, Russia.Alexander Zemlianichenko Jr/Russian Direct Investment Fund/AP/AAPOn Tuesday, Vladimir Putin announced Russia was...

Popular articles from Modern Australian

7 tips for a healthier office & work-lifeHow to supercharge your immune system for cold and flu seasonHow to Avoid Blocked Drains and Stinky OverflowCBD on Cyber Monday: Buying the Best for You5 Beginner Projects You Can Make with Arduino Starter KitWhy Your Outdoor Living Areas Might Benefit From TilesRetirement on the Road: Planning a Post-Retirement Australian Road TripDesign a Pool to Fit Your SpaceHow to Get TEFL Certification for Teaching English in ThailandHow to Find a Lawyer in Sydney for Your Legal RepresentationHow to Pre-Prepare For Your Retirement3 of the most common beginner’s mistakes in table tennisTips to Choose Regular Wear Bands for Your Brand New Apple WatchThe Benefits of Living a Healthy LifestyleHOW TO STUDY ART WITH WIKIART.ORG